Upregulation of Quinone Reductase by Glucosinolate Hydrolysis Products From Dietary Broccoli

Abstract

Publisher Summary This chapter focuses on the upregulation of the detoxification enzyme quinone reductase (QR) by crucifers, particularly broccoli, as it relates to cancer prevention. It is suggested that the upregulation of QR and other phase II detoxification enzymes may be the means by which cruciferous vegetables provide protection from cancer, either by destroying carcinogens before they have their effects, or more generally, by inhibiting the ability of reactive oxygen species to initiate or support carcinogenesis. Compounds that activate a battery of phase II enzymes, without activation of cytochrome P450, have been termed monofunctional inducers. The monofunctional inducers appear to share anticarcinogenic properties, making induction of QR a good biomarker of anticarcinogenic action. There are several advantages to the measurement of QR, rather than other detoxification enzymes, as a bioassay or biomarker of anticarcinogenic activity. Synergistic effects of glucosinolate metabolites are described. The chapter analyzes the variability in the effect of dietary cruciferous vegetables on induction of QR. Genotype variation in glucosinolate content of cruciferous vegetables is also elaborated in the chapter. The chapter describes the environmental effects on glucosinolate content of crucifers.